Patty Wood for The New York Times
Joe Milano, left, and Stephen Milano watched a commercial in a campaign against a ban on same-sex marriage. They appear in another one.

By RALPH BLUMENTHAL
Published: October 13, 2005

HOUSTON, Oct. 12 - In the television spot, two women sit side by side looking at the camera.

"What we have, all I can say, is the real thing," says Charlotte Simmons, a state social worker. "If something were to happen to me, I would want her to be taking care of me." Her partner, Anita, a retired Air Force administrator, breaks in. "I love Charlotte, no matter what," she says, "no matter what."

Flashing on the screen are the words: "You know people just like this."

The commercial, one of seven unveiled here Wednesday by the National Gay and Lesbian Task Force, is part of the opening advertising campaign in a battle over a ballot proposition to ban same-sex marriage in the Texas Constitution.

The volatile issue comes before Texas voters on Nov. 8, a year after 13 states changed their constitutions to ban same-sex marriage and half a year after Kansas. The television spots will appear several times a day for a week on three network affiliates in the Houston area. The final message of the spots: Vote no.

In an equally charged drive to pass the proposed amendment, the Texas Restoration Project, a network of conservative Christian pastors and others, has been mobilizing supporters to turn out for the vote.

A clergyman active in the effort, the Rev. Dwight McKissick of the Cornerstone Baptist Church in Arlington, said he hoped the state referendums would be steppingstones to amending the United States Constitution. "They're all free to practice their lifestyle," he said of gay people, "but not to redefine marriage."

Texas, which already prohibits same-sex marriage by law, is the only state voting on such a constitutional amendment in November, and odd-year elections with only local officials and state questions on the ballot usually draw low turnouts.

Only 12 percent of the electorate voted in 2003, and 7 percent in 2001. "No doubt this will be passed," predicted Bob Stein, professor of political science and dean of Social Sciences at Rice University here. But he said that with Harris County, including Houston, accounting for about 30 percent of the statewide vote and Houston generally more liberal than the rest of Texas - the county went to Senator John Kerry in 2004 - "the question is how it will pass."

Kelly Shackelford, a leader of a pro-amendment group called Texans for Marriage, said that a low turnout would favor opponents of the initiative known as Proposition 2 since, he said, "we clearly don't have the money they have, and all the gay rights groups are pitching in."

Mr. Shackelford added: "The majority of Texans believe marriage is between a man and a woman. The biggest issue we have is getting the word out. Most people have no idea this election is coming."

He said the amendment was needed despite the existing law because "state law is completely ineffectual against an activist state judge."

The amendment provides "that marriage in this state consists only of the union of one man and one woman." It also bars "this state or a political subdivision of this state from creating or recognizing any legal status identical or similar to marriage."

The measure was approved for the ballot by the Texas Legislature earlier this year. Gov. Rick Perry, a Republican up for re-election next year, then made a ceremony of signing his name to the measure, although it was not required, at an evangelical church in Fort Worth filled with "pro-family Christian friends," as an invitation from his office put it.

The National Gay and Lesbian Task Force said it spent $200,000 to develop the commercials and $15,000 to place them through next Tuesday.

It also said that it learned lessons from past defeats. Earlier campaigns around the country stressed protecting rights, said Dave Fleischer, the group's director of organizing and training. But he said, "it left the human beings out." These commercials feature four gay and lesbian couples and the parents of gay sons speaking frankly about their relationships and family issues.

The task force cited census figures showing, it said, 9,784 same-sex couples on record in the Houston area among a total of 42,912 in Texas.

The commercials feature, among others, the Rev. Carolyn J. Mobley, pastor of the Resurrection Metropolitan Community Church, and her partner, Adrain Bowie, a videographer. "When I asked her to marry me, it meant a long-term commitment," Ms. Bowie says on screen.

Ron and Mary Jo Dupre, parents of two gay sons, appear in another commercial. Mr. Dupre, a retired oil and gas operator and financier, describes himself as a "a typical redneck" whose first reaction upon learning about his sons was, "What did I do wrong?"

"I didn't do anything wrong" he says he realized.

In another spot, Ms. Dupre says, "I did not expect my daughter-in-law to be named Jeff, but I love him."

With the battle heating up, about two dozen church leaders and public officials, including the Harris County tax assessor and collector, Paul Bettencourt, rallied outside the Harris County courthouse Tuesday to urge support for the amendment. The campaign against the amendment, announced at a news conference at a Methodist church receptive to gays and lesbians, was praised by a prominent Baptist pastor, William A. Lawson of the Wheeler Avenue Baptist Church, and two public officials: state Representative Garnet Coleman, a Democrat from Houston, and Annise Parker, Houston's city controller, who has long been active in lesbian causes. "This is personal," she said of her interest. "This is about our lives, our ability to protect and provide for our families."